1. Field of the Invention
This invention relates to a method and system using delay signals to reduce or eliminate interference between paths in a communication network, in particular to an electronic circuit.
2. Description of the Related Art
Communication networks, in particular communication networks on integrated circuits, have numerous paths carrying signals from one device to other devices. Multiple paths that are placed near one another can lead to problems related to coupling and capacitative interference. The situation becomes more problematic when multiple paths carrying signals switching in the same direction run parallel to a single path switching in the opposite direction.
In cases of multiple paths carrying signals that switch opposite of a single path, the multiple paths are referred to as aggressors and the single path is referred to as a victim. Coupling effects do not have a noticeable effect upon aggressor signals with one another, because the signals of the aggressors are switching in the same direction. In a digital signal transmission, the rise of the signal from a driver connected to an aggressor path is not affected by signals from the other aggressor paths. Coupling effects, however, can have an effect upon the victim path's signal. In particular coupling effects lead to slower rise times of victim path signals. To compensate for slower rise times, victim path driver power is increased. The victim path driver is required to provide additional power to compensate for a slower rise time in order to get the signal out and to achieve proper signal level and timing requirements.
To alleviate the effects on victim paths by aggressor paths, the paths can be laid out to allow paths that carry signals that switch in the same direction to be placed near one another. This approach, however, leads to design constraints that require paths to be placed in limited positions and limit network architecture. In most situations, paths have opposing signals placed next to each other (e.g., send and receive signals to and from devices).
In certain designs, neutral paths such as ground paths (also known as shield lines) are available and placed between aggressors and victim paths, effectively shielding the victim path. Shield lines typically serve no function but are merely used to shield the victim path. The use of neutral paths or shield lines also leads to design considerations and network architecture constraints in laying out paths. Adding shield lines further adds to an increase in the space of the network. In an integrated circuit, minimizing size is highly desirable, and adding non-functional shield lines becomes counter productive to meeting the goal of minimizing size.